Numerical and experimental study of a CO2 multi-channel radiator used for space application

Abstract

This article presents a novel multi-channel condenser/radiator designed for mechanically pumped two-phase cooling systems in space. A numerical model coupling two-phase condensation heat transfer with thermal radiation is proposed to design and accurately predict the performance of the radiator, taking into account both single-phase and two-phase heat transfer occurring within the fluid channels. The performance assessment of the radiator is carried out in a thermal vacuum chamber with CO${}_2$ circulating through a closed cooling loop. The validation of the numerical model is confirmed by comparing the predicted results with the experimental data obtained. The comparison demonstrates good agreement with the discrepancy of 10% between the predictions and the actual measurements. The numerical method presented here is simpler compared to Computational Fluid Dynamics (CFD), making calculations more accessible, particularly for those without access to CFD tools. Additionally, this paper explores ways to simplify complex thermal radiation issues using surface-to-surface radiation models and the Monte Carlo method to calculate the view factor.